The rationale is that rather than just leave money to your beneficiaries and let them spend it as they wish, inducing them to engage in tasks considered to be improving
Beneficiaries will naturally be of differing characters and persuasions, some better formed and informed than others and can range from the very spoilt to the fairly sensible.
In terms of the Foundational Incentives, suitable trustees would have to be appointed to oversee proper implementation. Much will depend on the nature of the Incentive, the beneficiaries and the availability of suitable Trustees